1. Field of the Invention
The invention relates to improved thickening systems for cosmetic compositions, particularly those in lotion and cream form.
2. The Related Art
Aqueous cosmetic compositions often require thickeners to achieve an aesthetically pleasing viscosity. Fluids that flow with a watery consistency too rapidly run off the treated skin areas. For a cosmetic to be effective, it often must have substantivity. Thickeners provide this substantivity. Furthermore, low viscosity formulas which may be skin effective nevertheless through their wateriness signal ineffectiveness to the consumer. Products of watery consistency are also aesthetically displeasing to consumers with expectations of rich and creamy products.
Countless numbers of thickening agents are known in the literature. Perhaps this plethora intimates that not all thickening agents are equally effective for any particular type of formulation.
Difficulties also arise in aqueous systems containing water-soluble vitamins. These function as electrolytes that adversely affect anionic polymeric thickening agents.
Indeed, there are some formulations which are extremely difficult to thicken, and even if initially thickened may have storage stability problems. Low pH systems are particularly sensitive and difficult.
Accordingly, it is an object of the present invention to provide a thickener system and thickened cosmetic compositions of sufficiently aesthetically pleasing viscosity.
It is another object of the present invention to provide a thickening system for a cosmetic composition that will be effective even in the presence of water-soluble vitamins which may function as electrolytes.
It is another object of the present invention to provide thickening systems for cosmetic compositions that are effective at low pH.
These and other objects of the present invention will more readily become apparent from the description and examples which follow.